Fix OpenAPI example not showing (#3930)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

.changeset/four-clowns-begin.md

@@ -0,0 +1,5 @@
+---
+"@gitbook/react-openapi": patch
+---
+
+Fix OpenAPI example not showing

packages/react-openapi/src/OpenAPIMediaType.tsx

@@ -31,9 +31,15 @@ export function OpenAPIMediaTypeContent(props: {
     const { stateKey, items, selectIcon, context } = props;
     const state = useMediaTypesState(stateKey, items[0]?.key);
 
-    const examples = items.find((item) => item.key === state.key)?.examples ?? [];
+    const item = items.find((item) => item.key === state.key) ?? items[0];
 
-    if (!items.length && !examples.length) {
+    if (!item) {
+        return null;
+    }
+
+    const examples = item.examples;
+
+    if (!examples || !examples.length) {
         return null;
     }